mcs/delegate.cs

   1 //
   2 // delegate.cs: Delegate Handler
   3 //
   4 // Authors:
   5 //     Ravi Pratap (ravi@ximian.com)
   6 //     Miguel de Icaza (miguel@ximian.com)
   7 //     Marek Safar (marek.safar@gmail.com)
   8 //
   9 // Dual licensed under the terms of the MIT X11 or GNU GPL
  10 //
  11 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
  12 // Copyright 2003-2008 Novell, Inc (http://www.ximian.com)
  13 //
  14
  15 using System;
  16 using System.Collections;
  17 using System.Reflection;
  18 using System.Reflection.Emit;
  19 using System.Text;
  20
  21 namespace Mono.CSharp {
  22
  23         /// <summary>
  24         ///   Holds Delegates
  25         /// </summary>
  26         public class Delegate : DeclSpace, IMemberContainer
  27         {
  28                 FullNamedExpression ReturnType;
  29                 public ParametersCompiled      Parameters;
  30
  31                 public ConstructorBuilder ConstructorBuilder;
  32                 public MethodBuilder      InvokeBuilder;
  33                 public MethodBuilder      BeginInvokeBuilder;
  34                 public MethodBuilder      EndInvokeBuilder;
  35
  36                 Type ret_type;
  37
  38                 static string[] attribute_targets = new string [] { "type", "return" };
  39
  40                 Expression instance_expr;
  41                 MethodBase delegate_method;
  42                 ReturnParameter return_attributes;
  43
  44                 MemberCache member_cache;
  45
  46                 const MethodAttributes mattr = MethodAttributes.Public | MethodAttributes.HideBySig |
  47                         MethodAttributes.Virtual | MethodAttributes.NewSlot;
  48
  49                 const int AllowedModifiers =
  50                         Modifiers.NEW |
  51                         Modifiers.PUBLIC |
  52                         Modifiers.PROTECTED |
  53                         Modifiers.INTERNAL |
  54                         Modifiers.UNSAFE |
  55                         Modifiers.PRIVATE;
  56
  57                 public Delegate (NamespaceEntry ns, DeclSpace parent, FullNamedExpression type,
  58                                  int mod_flags, MemberName name, ParametersCompiled param_list,
  59                                  Attributes attrs)
  60                         : base (ns, parent, name, attrs)
  61
  62                 {
  63                         this.ReturnType = type;
  64                         ModFlags        = Modifiers.Check (AllowedModifiers, mod_flags,
  65                                                            IsTopLevel ? Modifiers.INTERNAL :
  66                                                            Modifiers.PRIVATE, name.Location);
  67                         Parameters      = param_list;
  68                 }
  69
  70                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
  71                 {
  72                         if (a.Target == AttributeTargets.ReturnValue) {
  73                                 if (return_attributes == null)
  74                                         return_attributes = new ReturnParameter (InvokeBuilder, Location);
  75
  76                                 return_attributes.ApplyAttributeBuilder (a, cb, pa);
  77                                 return;
  78                         }
  79
  80                         base.ApplyAttributeBuilder (a, cb, pa);
  81                 }
  82
  83                 public override TypeBuilder DefineType ()
  84                 {
  85                         if (TypeBuilder != null)
  86                                 return TypeBuilder;
  87
  88                         if (IsTopLevel) {
  89                                 if (TypeManager.NamespaceClash (Name, Location))
  90                                         return null;
  91
  92                                 ModuleBuilder builder = Module.Builder;
  93
  94                                 TypeBuilder = builder.DefineType (
  95                                         Name, TypeAttr, TypeManager.multicast_delegate_type);
  96                         } else {
  97                                 TypeBuilder builder = Parent.TypeBuilder;
  98
  99                                 string name = Name.Substring (1 + Name.LastIndexOf ('.'));
 100                                 TypeBuilder = builder.DefineNestedType (
 101                                         name, TypeAttr, TypeManager.multicast_delegate_type);
 102                         }
 103
 104                         TypeManager.AddUserType (this);
 105
 106 #if GMCS_SOURCE
 107                         if (IsGeneric) {
 108                                 string[] param_names = new string [TypeParameters.Length];
 109                                 for (int i = 0; i < TypeParameters.Length; i++)
 110                                         param_names [i] = TypeParameters [i].Name;
 111
 112                                 GenericTypeParameterBuilder[] gen_params;
 113                                 gen_params = TypeBuilder.DefineGenericParameters (param_names);
 114
 115                                 int offset = CountTypeParameters - CurrentTypeParameters.Length;
 116                                 for (int i = offset; i < gen_params.Length; i++)
 117                                         CurrentTypeParameters [i - offset].Define (gen_params [i]);
 118
 119                                 foreach (TypeParameter type_param in CurrentTypeParameters) {
 120                                         if (!type_param.Resolve (this))
 121                                                 return null;
 122                                 }
 123
 124                                 Expression current = new SimpleName (
 125                                         MemberName.Basename, TypeParameters, Location);
 126                                 current = current.ResolveAsTypeTerminal (this, false);
 127                                 if (current == null)
 128                                         return null;
 129
 130                                 CurrentType = current.Type;
 131                         }
 132 #endif
 133
 134                         return TypeBuilder;
 135                 }
 136
 137                 public override bool Define ()
 138                 {
 139                         if (IsGeneric) {
 140                                 foreach (TypeParameter type_param in TypeParameters) {
 141                                         if (!type_param.Resolve (this))
 142                                                 return false;
 143                                 }
 144
 145                                 foreach (TypeParameter type_param in TypeParameters) {
 146                                         if (!type_param.DefineType (this))
 147                                                 return false;
 148                                 }
 149                         }
 150
 151                         member_cache = new MemberCache (TypeManager.multicast_delegate_type, this);
 152
 153                         // FIXME: POSSIBLY make this static, as it is always constant
 154                         //
 155                         Type [] const_arg_types = new Type [2];
 156                         const_arg_types [0] = TypeManager.object_type;
 157                         const_arg_types [1] = TypeManager.intptr_type;
 158
 159                         const MethodAttributes ctor_mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
 160                                 MethodAttributes.HideBySig | MethodAttributes.Public;
 161
 162                         ConstructorBuilder = TypeBuilder.DefineConstructor (ctor_mattr,
 163                                                                             CallingConventions.Standard,
 164                                                                             const_arg_types);
 165
 166                         ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");
 167                         ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");
 168                         //
 169                         // HACK because System.Reflection.Emit is lame
 170                         //
 171                         IParameterData [] fixed_pars = new IParameterData [] {
 172                                 new ParameterData ("object", Parameter.Modifier.NONE),
 173                                 new ParameterData ("method", Parameter.Modifier.NONE)
 174                         };
 175
 176                         AParametersCollection const_parameters = new ParametersImported (
 177                                 fixed_pars,
 178                                 new Type[] { TypeManager.object_type, TypeManager.intptr_type });
 179
 180                         TypeManager.RegisterMethod (ConstructorBuilder, const_parameters);
 181                         member_cache.AddMember (ConstructorBuilder, this);
 182
 183                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 184
 185                         //
 186                         // Here the various methods like Invoke, BeginInvoke etc are defined
 187                         //
 188                         // First, call the `out of band' special method for
 189                         // defining recursively any types we need:
 190
 191                         if (!Parameters.Resolve (this))
 192                                 return false;
 193
 194                         //
 195                         // Invoke method
 196                         //
 197
 198                         // Check accessibility
 199                         foreach (Type partype in Parameters.Types){
 200                                 if (!IsAccessibleAs (partype)) {
 201                                         Report.SymbolRelatedToPreviousError (partype);
 202                                         Report.Error (59, Location,
 203                                                       "Inconsistent accessibility: parameter type `{0}' is less accessible than delegate `{1}'",
 204                                                       TypeManager.CSharpName (partype),
 205                                                       GetSignatureForError ());
 206                                         return false;
 207                                 }
 208                         }
 209
 210                         ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
 211                         if (ReturnType == null)
 212                                 return false;
 213
 214                         ret_type = ReturnType.Type;
 215
 216                         if (!IsAccessibleAs (ret_type)) {
 217                                 Report.SymbolRelatedToPreviousError (ret_type);
 218                                 Report.Error (58, Location,
 219                                               "Inconsistent accessibility: return type `" +
 220                                               TypeManager.CSharpName (ret_type) + "' is less " +
 221                                               "accessible than delegate `" + GetSignatureForError () + "'");
 222                                 return false;
 223                         }
 224
 225                         CheckProtectedModifier ();
 226
 227                         if (RootContext.StdLib && TypeManager.IsSpecialType (ret_type)) {
 228                                 Method.Error1599 (Location, ret_type);
 229                                 return false;
 230                         }
 231
 232                         TypeManager.CheckTypeVariance (ret_type, Variance.Covariant, this);
 233
 234                         //
 235                         // We don't have to check any others because they are all
 236                         // guaranteed to be accessible - they are standard types.
 237                         //
 238
 239                         CallingConventions cc = Parameters.CallingConvention;
 240
 241                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
 242                                                                   mattr,
 243                                                                   cc,
 244                                                                   ret_type,
 245                                                                   Parameters.GetEmitTypes ());
 246
 247                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 248
 249                         TypeManager.RegisterMethod (InvokeBuilder, Parameters);
 250                         member_cache.AddMember (InvokeBuilder, this);
 251
 252                         if (TypeManager.iasyncresult_type != null && TypeManager.asynccallback_type != null) {
 253                                 DefineAsyncMethods (cc);
 254                         }
 255
 256                         return true;
 257                 }
 258
 259                 void DefineAsyncMethods (CallingConventions cc)
 260                 {
 261                         //
 262                         // BeginInvoke
 263                         //
 264                         ParametersCompiled async_parameters = ParametersCompiled.MergeGenerated (Parameters, false,
 265                                 new Parameter [] {
 266                                         new Parameter (null, "callback", Parameter.Modifier.NONE, null, Location),
 267                                         new Parameter (null, "object", Parameter.Modifier.NONE, null, Location)
 268                                 },
 269                                 new Type [] {
 270                                         TypeManager.asynccallback_type,
 271                                         TypeManager.object_type
 272                                 }
 273                         );
 274
 275                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
 276                                 mattr, cc, TypeManager.iasyncresult_type, async_parameters.GetEmitTypes ());
 277
 278                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 279                         TypeManager.RegisterMethod (BeginInvokeBuilder, async_parameters);
 280                         member_cache.AddMember (BeginInvokeBuilder, this);
 281
 282                         //
 283                         // EndInvoke is a bit more interesting, all the parameters labeled as
 284                         // out or ref have to be duplicated here.
 285                         //
 286
 287                         //
 288                         // Define parameters, and count out/ref parameters
 289                         //
 290                         ParametersCompiled end_parameters;
 291                         int out_params = 0;
 292
 293                         foreach (Parameter p in Parameters.FixedParameters) {
 294                                 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
 295                                         ++out_params;
 296                         }
 297
 298                         if (out_params > 0) {
 299                                 Type [] end_param_types = new Type [out_params];
 300                                 Parameter[] end_params = new Parameter [out_params];
 301
 302                                 int param = 0;
 303                                 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
 304                                         Parameter p = Parameters [i];
 305                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
 306                                                 continue;
 307
 308                                         end_param_types [param] = Parameters.Types [i];
 309                                         end_params [param] = p;
 310                                         ++param;
 311                                 }
 312                                 end_parameters = ParametersCompiled.CreateFullyResolved (end_params, end_param_types);
 313                         } else {
 314                                 end_parameters = ParametersCompiled.EmptyReadOnlyParameters;
 315                         }
 316
 317                         end_parameters = ParametersCompiled.MergeGenerated (end_parameters, false,
 318                                 new Parameter (null, "result", Parameter.Modifier.NONE, null, Location), TypeManager.iasyncresult_type);
 319
 320                         //
 321                         // Create method, define parameters, register parameters with type system
 322                         //
 323                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_parameters.GetEmitTypes ());
 324                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 325
 326                         end_parameters.ApplyAttributes (EndInvokeBuilder);
 327                         TypeManager.RegisterMethod (EndInvokeBuilder, end_parameters);
 328                         member_cache.AddMember (EndInvokeBuilder, this);
 329                 }
 330
 331                 public override void Emit ()
 332                 {
 333                         Parameters.ApplyAttributes (InvokeBuilder);
 334
 335                         if (BeginInvokeBuilder != null) {
 336                                 ParametersCompiled p = (ParametersCompiled) TypeManager.GetParameterData (BeginInvokeBuilder);
 337                                 p.ApplyAttributes (BeginInvokeBuilder);
 338                         }
 339
 340                         if (OptAttributes != null) {
 341                                 OptAttributes.Emit ();
 342                         }
 343
 344                         base.Emit ();
 345                 }
 346
 347                 protected override TypeAttributes TypeAttr {
 348                         get {
 349                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 350                                         TypeAttributes.Class | TypeAttributes.Sealed |
 351                                         base.TypeAttr;
 352                         }
 353                 }
 354
 355                 public override string[] ValidAttributeTargets {
 356                         get {
 357                                 return attribute_targets;
 358                         }
 359                 }
 360
 361                 //TODO: duplicate
 362                 protected override bool VerifyClsCompliance ()
 363                 {
 364                         if (!base.VerifyClsCompliance ()) {
 365                                 return false;
 366                         }
 367
 368                         Parameters.VerifyClsCompliance ();
 369
 370                         if (!AttributeTester.IsClsCompliant (ReturnType.Type)) {
 371                                 Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
 372                                         GetSignatureForError ());
 373                         }
 374                         return true;
 375                 }
 376
 377
 378                 public static ConstructorInfo GetConstructor (Type container_type, Type delegate_type)
 379                 {
 380                         Type dt = delegate_type;
 381                         Type[] g_args = null;
 382                         if (TypeManager.IsGenericType (delegate_type)) {
 383                                 g_args = TypeManager.GetTypeArguments (delegate_type);
 384                                 delegate_type = TypeManager.DropGenericTypeArguments (delegate_type);
 385                         }
 386
 387                         Delegate d = TypeManager.LookupDelegate (delegate_type);
 388                         if (d != null) {
 389 #if GMCS_SOURCE
 390                                 if (g_args != null)
 391                                         return TypeBuilder.GetConstructor (dt, d.ConstructorBuilder);
 392 #endif
 393                                 return d.ConstructorBuilder;
 394                         }
 395
 396                         Expression ml = Expression.MemberLookup (container_type,
 397                                 null, dt, ConstructorInfo.ConstructorName, MemberTypes.Constructor,
 398                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, Location.Null);
 399
 400                         MethodGroupExpr mg = ml as MethodGroupExpr;
 401                         if (mg == null) {
 402                                 Report.Error (-100, Location.Null, "Internal error: could not find delegate constructor!");
 403                                 // FIXME: null will cause a crash later
 404                                 return null;
 405                         }
 406
 407                         return (ConstructorInfo) mg.Methods[0];
 408                 }
 409
 410                 //
 411                 // Returns the MethodBase for "Invoke" from a delegate type, this is used
 412                 // to extract the signature of a delegate.
 413                 //
 414                 public static MethodInfo GetInvokeMethod (Type container_type, Type delegate_type)
 415                 {
 416                         Type dt = delegate_type;
 417
 418                         Type[] g_args = null;
 419                         if (TypeManager.IsGenericType (delegate_type)) {
 420                                 g_args = TypeManager.GetTypeArguments (delegate_type);
 421                                 delegate_type = TypeManager.DropGenericTypeArguments (delegate_type);
 422                         }
 423
 424                         Delegate d = TypeManager.LookupDelegate (delegate_type);
 425                         MethodInfo invoke;
 426                         if (d != null) {
 427 #if GMCS_SOURCE
 428                                 if (g_args != null) {
 429                                         invoke = TypeBuilder.GetMethod (dt, d.InvokeBuilder);
 430 #if MS_COMPATIBLE
 431                                         ParametersCompiled p = (ParametersCompiled) d.Parameters.InflateTypes (g_args, g_args);
 432                                         TypeManager.RegisterMethod (invoke, p);
 433 #endif
 434                                         return invoke;
 435                                 }
 436 #endif
 437                                 return d.InvokeBuilder;
 438                         }
 439
 440                         Expression ml = Expression.MemberLookup (container_type, null, dt,
 441                                 "Invoke", Location.Null);
 442
 443                         MethodGroupExpr mg = ml as MethodGroupExpr;
 444                         if (mg == null) {
 445                                 Report.Error (-100, Location.Null, "Internal error: could not find Invoke method!");
 446                                 // FIXME: null will cause a crash later
 447                                 return null;
 448                         }
 449
 450                         invoke = (MethodInfo) mg.Methods[0];
 451 #if MS_COMPATIBLE
 452                         if (g_args != null) {
 453                                 AParametersCollection p = TypeManager.GetParameterData (invoke);
 454                                 p = p.InflateTypes (g_args, g_args);
 455                                 TypeManager.RegisterMethod (invoke, p);
 456                                 return invoke;
 457                         }
 458 #endif
 459
 460                         return invoke;
 461                 }
 462
 463                 //
 464                 // 15.2 Delegate compatibility
 465                 //
 466                 public static bool IsTypeCovariant (Expression a, Type b)
 467                 {
 468                         //
 469                         // For each value parameter (a parameter with no ref or out modifier), an
 470                         // identity conversion or implicit reference conversion exists from the
 471                         // parameter type in D to the corresponding parameter type in M
 472                         //
 473                         if (a.Type == b)
 474                                 return true;
 475
 476                         if (RootContext.Version == LanguageVersion.ISO_1)
 477                                 return false;
 478
 479                         return Convert.ImplicitReferenceConversionExists (a, b);
 480                 }
 481
 482                 /// <summary>
 483                 ///  Verifies whether the method in question is compatible with the delegate
 484                 ///  Returns the method itself if okay and null if not.
 485                 /// </summary>
 486                 public static MethodBase VerifyMethod (Type container_type, Type delegate_type,
 487                                                        MethodGroupExpr old_mg, MethodBase mb)
 488                 {
 489                         bool is_method_definition = TypeManager.IsGenericMethodDefinition (mb);
 490
 491                         MethodInfo invoke_mb = GetInvokeMethod (container_type, delegate_type);
 492                         if (invoke_mb == null)
 493                                 return null;
 494
 495                         if (is_method_definition)
 496                                 invoke_mb = (MethodInfo) TypeManager.DropGenericMethodArguments (invoke_mb);
 497
 498                         AParametersCollection invoke_pd = TypeManager.GetParameterData (invoke_mb);
 499
 500 #if GMCS_SOURCE
 501                         if (!is_method_definition && old_mg.type_arguments == null &&
 502                             !TypeManager.InferTypeArguments (invoke_pd, ref mb))
 503                                 return null;
 504 #endif
 505                         AParametersCollection pd = TypeManager.GetParameterData (mb);
 506
 507                         if (invoke_pd.Count != pd.Count)
 508                                 return null;
 509
 510                         for (int i = pd.Count; i > 0; ) {
 511                                 i--;
 512
 513                                 Type invoke_pd_type = invoke_pd.Types [i];
 514                                 Type pd_type = pd.Types [i];
 515                                 Parameter.Modifier invoke_pd_type_mod = invoke_pd.FixedParameters [i].ModFlags;
 516                                 Parameter.Modifier pd_type_mod = pd.FixedParameters [i].ModFlags;
 517
 518                                 invoke_pd_type_mod &= ~Parameter.Modifier.PARAMS;
 519                                 pd_type_mod &= ~Parameter.Modifier.PARAMS;
 520
 521                                 if (invoke_pd_type_mod != pd_type_mod)
 522                                         return null;
 523
 524                                 if (TypeManager.IsEqual (invoke_pd_type, pd_type))
 525                                         continue;
 526
 527                                 if (IsTypeCovariant (new EmptyExpression (invoke_pd_type), pd_type))
 528                                         continue;
 529
 530                                 return null;
 531                         }
 532
 533                         Type invoke_mb_retval = ((MethodInfo) invoke_mb).ReturnType;
 534                         Type mb_retval = ((MethodInfo) mb).ReturnType;
 535                         if (TypeManager.TypeToCoreType (invoke_mb_retval) == TypeManager.TypeToCoreType (mb_retval))
 536                                 return mb;
 537
 538                         //if (!IsTypeCovariant (mb_retval, invoke_mb_retval))
 539                         //      return null;
 540
 541                         if (RootContext.Version == LanguageVersion.ISO_1)
 542                                 return null;
 543
 544                         return mb;
 545                 }
 546
 547                 // <summary>
 548                 //  Verifies whether the invocation arguments are compatible with the
 549                 //  delegate's target method
 550                 // </summary>
 551                 public static bool VerifyApplicability (EmitContext ec, Type delegate_type, ref Arguments args, Location loc)
 552                 {
 553                         int arg_count;
 554
 555                         if (args == null)
 556                                 arg_count = 0;
 557                         else
 558                                 arg_count = args.Count;
 559
 560                         MethodBase mb = GetInvokeMethod (ec.ContainerType, delegate_type);
 561                         MethodGroupExpr me = new MethodGroupExpr (new MemberInfo [] { mb }, delegate_type, loc);
 562
 563                         AParametersCollection pd = TypeManager.GetParameterData (mb);
 564
 565                         int pd_count = pd.Count;
 566
 567                         bool params_method = pd.HasParams;
 568                         bool is_params_applicable = false;
 569                         bool is_applicable = me.IsApplicable (ec, ref args, arg_count, ref mb, ref is_params_applicable) == 0;
 570                         if (args != null)
 571                                 arg_count = args.Count;
 572
 573                         if (!is_applicable && !params_method && arg_count != pd_count) {
 574                                 Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
 575                                         TypeManager.CSharpName (delegate_type), arg_count.ToString ());
 576                                 return false;
 577                         }
 578
 579                         return me.VerifyArgumentsCompat (
 580                                         ec, ref args, arg_count, mb,
 581                                         is_params_applicable || (!is_applicable && params_method),
 582                                         false, loc);
 583                 }
 584
 585                 public static string FullDelegateDesc (MethodBase invoke_method)
 586                 {
 587                         return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
 588                 }
 589
 590                 public override MemberCache MemberCache {
 591                         get {
 592                                 return member_cache;
 593                         }
 594                 }
 595
 596                 public Expression InstanceExpression {
 597                         get {
 598                                 return instance_expr;
 599                         }
 600                         set {
 601                                 instance_expr = value;
 602                         }
 603                 }
 604
 605                 public MethodBase TargetMethod {
 606                         get {
 607                                 return delegate_method;
 608                         }
 609                         set {
 610                                 delegate_method = value;
 611                         }
 612                 }
 613
 614                 public Type TargetReturnType {
 615                         get {
 616                                 return ret_type;
 617                         }
 618                 }
 619
 620                 public override AttributeTargets AttributeTargets {
 621                         get {
 622                                 return AttributeTargets.Delegate;
 623                         }
 624                 }
 625
 626                 //
 627                 //   Represents header string for documentation comment.
 628                 //
 629                 public override string DocCommentHeader {
 630                         get { return "T:"; }
 631                 }
 632
 633                 #region IMemberContainer Members
 634
 635                 string IMemberContainer.Name
 636                 {
 637                         get { throw new NotImplementedException (); }
 638                 }
 639
 640                 Type IMemberContainer.Type
 641                 {
 642                         get { throw new NotImplementedException (); }
 643                 }
 644
 645                 MemberCache IMemberContainer.BaseCache
 646                 {
 647                         get { throw new NotImplementedException (); }
 648                 }
 649
 650                 bool IMemberContainer.IsInterface {
 651                         get {
 652                                 return false;
 653                         }
 654                 }
 655
 656                 MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
 657                 {
 658                         throw new NotImplementedException ();
 659                 }
 660
 661                 #endregion
 662         }
 663
 664         //
 665         // Base class for `NewDelegate' and `ImplicitDelegateCreation'
 666         //
 667         public abstract class DelegateCreation : Expression, MethodGroupExpr.IErrorHandler
 668         {
 669                 protected ConstructorInfo constructor_method;
 670                 protected MethodInfo delegate_method;
 671                 // We keep this to handle IsBase only
 672                 protected MethodGroupExpr method_group;
 673                 protected Expression delegate_instance_expression;
 674
 675                 // TODO: Should either cache it or use interface to abstract it
 676                 public static Arguments CreateDelegateMethodArguments (AParametersCollection pd, Location loc)
 677                 {
 678                         Arguments delegate_arguments = new Arguments (pd.Count);
 679                         for (int i = 0; i < pd.Count; ++i) {
 680                                 Argument.AType atype_modifier;
 681                                 Type atype = pd.Types [i];
 682                                 switch (pd.FixedParameters [i].ModFlags) {
 683                                 case Parameter.Modifier.REF:
 684                                         atype_modifier = Argument.AType.Ref;
 685                                         //atype = atype.GetElementType ();
 686                                         break;
 687                                 case Parameter.Modifier.OUT:
 688                                         atype_modifier = Argument.AType.Out;
 689                                         //atype = atype.GetElementType ();
 690                                         break;
 691                                 default:
 692                                         atype_modifier = 0;
 693                                         break;
 694                                 }
 695                                 delegate_arguments.Add (new Argument (new TypeExpression (atype, loc), atype_modifier));
 696                         }
 697                         return delegate_arguments;
 698                 }
 699
 700                 public override Expression CreateExpressionTree (EmitContext ec)
 701                 {
 702                         MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
 703
 704                         Arguments args = new Arguments (3);
 705                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 706                         args.Add (new Argument (new NullLiteral (loc)));
 707                         args.Add (new Argument (new TypeOfMethodInfo (delegate_method, loc)));
 708                         Expression e = new Invocation (ma, args).Resolve (ec);
 709                         if (e == null)
 710                                 return null;
 711
 712                         e = Convert.ExplicitConversion (ec, e, type, loc);
 713                         if (e == null)
 714                                 return null;
 715
 716                         return e.CreateExpressionTree (ec);
 717                 }
 718
 719                 public override Expression DoResolve (EmitContext ec)
 720                 {
 721                         constructor_method = Delegate.GetConstructor (ec.ContainerType, type);
 722
 723                         MethodInfo invoke_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
 724                         method_group.DelegateType = type;
 725                         method_group.CustomErrorHandler = this;
 726
 727                         Arguments arguments = CreateDelegateMethodArguments (TypeManager.GetParameterData (invoke_method), loc);
 728                         method_group = method_group.OverloadResolve (ec, ref arguments, false, loc);
 729                         if (method_group == null)
 730                                 return null;
 731
 732                         delegate_method = (MethodInfo) method_group;
 733
 734                         if (TypeManager.IsNullableType (delegate_method.DeclaringType)) {
 735                                 Report.Error (1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
 736                                         TypeManager.GetFullNameSignature (delegate_method));
 737                                 return null;
 738                         }
 739
 740                         Invocation.IsSpecialMethodInvocation (delegate_method, loc);
 741
 742                         ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
 743                         if (emg != null) {
 744                                 delegate_instance_expression = emg.ExtensionExpression;
 745                                 Type e_type = delegate_instance_expression.Type;
 746                                 if (TypeManager.IsValueType (e_type)) {
 747                                         Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
 748                                                 TypeManager.CSharpSignature (delegate_method), TypeManager.CSharpName (e_type));
 749                                 }
 750                         }
 751
 752                         Type rt = TypeManager.TypeToCoreType (delegate_method.ReturnType);
 753                         Expression ret_expr = new TypeExpression (rt, loc);
 754                         if (!Delegate.IsTypeCovariant (ret_expr, (TypeManager.TypeToCoreType (invoke_method.ReturnType)))) {
 755                                 Error_ConversionFailed (ec, delegate_method, ret_expr);
 756                         }
 757
 758                         if (Invocation.IsMethodExcluded (delegate_method, loc)) {
 759                                 Report.SymbolRelatedToPreviousError (delegate_method);
 760                                 MethodOrOperator m = TypeManager.GetMethod (delegate_method) as MethodOrOperator;
 761                                 if (m != null && m.IsPartialDefinition) {
 762                                         Report.Error (762, loc, "Cannot create delegate from partial method declaration `{0}'",
 763                                                 TypeManager.CSharpSignature (delegate_method));
 764                                 } else {
 765                                         Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
 766                                                 TypeManager.CSharpSignature (delegate_method));
 767                                 }
 768                         }
 769
 770                         DoResolveInstanceExpression (ec);
 771                         eclass = ExprClass.Value;
 772                         return this;
 773                 }
 774
 775                 void DoResolveInstanceExpression (EmitContext ec)
 776                 {
 777                         //
 778                         // Argument is another delegate
 779                         //
 780                         if (delegate_instance_expression != null)
 781                                 return;
 782
 783                         Expression instance = method_group.InstanceExpression;
 784                         if (instance != null && instance != EmptyExpression.Null) {
 785                                 delegate_instance_expression = instance;
 786                                 Type instance_type = delegate_instance_expression.Type;
 787                                 if (TypeManager.IsValueType (instance_type) || TypeManager.IsGenericParameter (instance_type)) {
 788                                         delegate_instance_expression = new BoxedCast (
 789                                                 delegate_instance_expression, TypeManager.object_type);
 790                                 }
 791                         } else if (!delegate_method.IsStatic && !ec.IsStatic) {
 792                                 delegate_instance_expression = ec.GetThis (loc);
 793                         }
 794                 }
 795
 796                 public override void Emit (EmitContext ec)
 797                 {
 798                         if (delegate_instance_expression == null)
 799                                 ec.ig.Emit (OpCodes.Ldnull);
 800                         else
 801                                 delegate_instance_expression.Emit (ec);
 802
 803                         if (!delegate_method.DeclaringType.IsSealed && delegate_method.IsVirtual && !method_group.IsBase) {
 804                                 ec.ig.Emit (OpCodes.Dup);
 805                                 ec.ig.Emit (OpCodes.Ldvirtftn, delegate_method);
 806                         } else {
 807                                 ec.ig.Emit (OpCodes.Ldftn, delegate_method);
 808                         }
 809
 810                         ec.ig.Emit (OpCodes.Newobj, constructor_method);
 811                 }
 812
 813                 void Error_ConversionFailed (EmitContext ec, MethodBase method, Expression return_type)
 814                 {
 815                         MethodInfo invoke_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
 816                         string member_name = delegate_instance_expression != null ?
 817                                 Delegate.FullDelegateDesc (method) :
 818                                 TypeManager.GetFullNameSignature (method);
 819
 820                         Report.SymbolRelatedToPreviousError (type);
 821                         Report.SymbolRelatedToPreviousError (method);
 822                         if (RootContext.Version == LanguageVersion.ISO_1) {
 823                                 Report.Error (410, loc, "A method or delegate `{0} {1}' parameters and return type must be same as delegate `{2} {3}' parameters and return type",
 824                                         TypeManager.CSharpName (((MethodInfo) method).ReturnType), member_name,
 825                                         TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
 826                                 return;
 827                         }
 828                         if (return_type == null) {
 829                                 Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
 830                                         member_name, Delegate.FullDelegateDesc (invoke_method));
 831                                 return;
 832                         }
 833
 834                         Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
 835                                 return_type.GetSignatureForError (), member_name,
 836                                 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
 837                 }
 838
 839                 public static MethodBase ImplicitStandardConversionExists (MethodGroupExpr mg, Type target_type)
 840                 {
 841                         if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
 842                                 return null;
 843
 844                         foreach (MethodInfo mi in mg.Methods){
 845                                 MethodBase mb = Delegate.VerifyMethod (mg.DeclaringType, target_type, mg, mi);
 846                                 if (mb != null)
 847                                         return mb;
 848                         }
 849                         return null;
 850                 }
 851
 852                 public override void MutateHoistedGenericType (AnonymousMethodStorey storey)
 853                 {
 854                         if (delegate_instance_expression != null)
 855                                 delegate_instance_expression.MutateHoistedGenericType (storey);
 856
 857                         delegate_method = storey.MutateGenericMethod (delegate_method);
 858                         constructor_method = storey.MutateConstructor (constructor_method);
 859                 }
 860
 861                 #region IErrorHandler Members
 862
 863                 public bool NoExactMatch (EmitContext ec, MethodBase method)
 864                 {
 865                         if (TypeManager.IsGenericMethod (method))
 866                                 return false;
 867
 868                         Error_ConversionFailed (ec, method, null);
 869                         return true;
 870                 }
 871
 872                 public bool AmbiguousCall (MethodBase ambiguous)
 873                 {
 874                         return false;
 875                 }
 876
 877                 #endregion
 878         }
 879
 880         //
 881         // Created from the conversion code
 882         //
 883         public class ImplicitDelegateCreation : DelegateCreation
 884         {
 885                 ImplicitDelegateCreation (Type t, MethodGroupExpr mg, Location l)
 886                 {
 887                         type = t;
 888                         this.method_group = mg;
 889                         loc = l;
 890                 }
 891
 892                 static public Expression Create (EmitContext ec, MethodGroupExpr mge,
 893                                                  Type target_type, Location loc)
 894                 {
 895                         ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, mge, loc);
 896                         return d.DoResolve (ec);
 897                 }
 898         }
 899
 900         //
 901         // A delegate-creation-expression, invoked from the `New' class
 902         //
 903         public class NewDelegate : DelegateCreation
 904         {
 905                 public Arguments Arguments;
 906
 907                 //
 908                 // This constructor is invoked from the `New' expression
 909                 //
 910                 public NewDelegate (Type type, Arguments Arguments, Location loc)
 911                 {
 912                         this.type = type;
 913                         this.Arguments = Arguments;
 914                         this.loc  = loc;
 915                 }
 916
 917                 public override Expression DoResolve (EmitContext ec)
 918                 {
 919                         if (Arguments == null || Arguments.Count != 1) {
 920                                 Error_InvalidDelegateArgument ();
 921                                 return null;
 922                         }
 923
 924                         Argument a = Arguments [0];
 925                         if (!a.ResolveMethodGroup (ec))
 926                                 return null;
 927
 928                         Expression e = a.Expr;
 929
 930                         AnonymousMethodExpression ame = e as AnonymousMethodExpression;
 931                         if (ame != null && RootContext.Version != LanguageVersion.ISO_1) {
 932                                 e = ame.Compatible (ec, type);
 933                                 if (e == null)
 934                                         return null;
 935
 936                                 return e.Resolve (ec);
 937                         }
 938
 939                         method_group = e as MethodGroupExpr;
 940                         if (method_group == null) {
 941                                 if (!TypeManager.IsDelegateType (e.Type)) {
 942                                         e.Error_UnexpectedKind (ResolveFlags.MethodGroup | ResolveFlags.Type, loc);
 943                                         return null;
 944                                 }
 945
 946                                 //
 947                                 // An argument is not a method but another delegate
 948                                 //
 949                                 delegate_instance_expression = e;
 950                                 method_group = new MethodGroupExpr (new MemberInfo [] {
 951                                         Delegate.GetInvokeMethod (ec.ContainerType, e.Type) }, e.Type, loc);
 952                         }
 953
 954                         return base.DoResolve (ec);
 955                 }
 956
 957                 void Error_InvalidDelegateArgument ()
 958                 {
 959                         Report.Error (149, loc, "Method name expected");
 960                 }
 961         }
 962
 963         public class DelegateInvocation : ExpressionStatement {
 964
 965                 readonly Expression InstanceExpr;
 966                 Arguments  Arguments;
 967                 MethodInfo method;
 968
 969                 public DelegateInvocation (Expression instance_expr, Arguments args, Location loc)
 970                 {
 971                         this.InstanceExpr = instance_expr;
 972                         this.Arguments = args;
 973                         this.loc = loc;
 974                 }
 975
 976                 public override Expression CreateExpressionTree (EmitContext ec)
 977                 {
 978                         Arguments args = Arguments.CreateForExpressionTree (ec, Arguments,
 979                                 InstanceExpr.CreateExpressionTree (ec));
 980
 981                         return CreateExpressionFactoryCall ("Invoke", args);
 982                 }
 983
 984                 public override Expression DoResolve (EmitContext ec)
 985                 {
 986                         if (InstanceExpr is EventExpr) {
 987                                 ((EventExpr) InstanceExpr).Error_CannotAssign ();
 988                                 return null;
 989                         }
 990
 991                         Type del_type = InstanceExpr.Type;
 992                         if (del_type == null)
 993                                 return null;
 994
 995                         if (Arguments != null){
 996                                 Arguments.Resolve (ec);
 997                         }
 998
 999                         if (!Delegate.VerifyApplicability (ec, del_type, ref Arguments, loc))
1000                                 return null;
1001
1002                         method = Delegate.GetInvokeMethod (ec.ContainerType, del_type);
1003                         type = TypeManager.TypeToCoreType (method.ReturnType);
1004                         eclass = ExprClass.Value;
1005
1006                         return this;
1007                 }
1008
1009                 public override void Emit (EmitContext ec)
1010                 {
1011                         //
1012                         // Invocation on delegates call the virtual Invoke member
1013                         // so we are always `instance' calls
1014                         //
1015                         Invocation.EmitCall (ec, false, InstanceExpr, method, Arguments, loc);
1016                 }
1017
1018                 public override void EmitStatement (EmitContext ec)
1019                 {
1020                         Emit (ec);
1021                         //
1022                         // Pop the return value if there is one
1023                         //
1024                         if (type != TypeManager.void_type)
1025                                 ec.ig.Emit (OpCodes.Pop);
1026                 }
1027
1028                 public override void MutateHoistedGenericType (AnonymousMethodStorey storey)
1029                 {
1030                         method = storey.MutateGenericMethod (method);
1031                         type = storey.MutateType (type);
1032
1033                         if (Arguments != null)
1034                                 Arguments.MutateHoistedGenericType (storey);
1035
1036                         InstanceExpr.MutateHoistedGenericType (storey);
1037                 }
1038         }
1039 }